Prognostic Value of A/T/N Biomarkers: Comparing Plasma and Imaging Modalities in Alzheimer Disease.

Background: Alzheimer disease (AD) is characterized by amyloid-β plaques (A), tau tangles (T), and neurodegeneration (N), collectively defining the ATN framework. While imaging biomarkers are well-established, the prognostic value of plasma biomarkers in predicting cognitive decline remains underexplored. This study compares plasma and imaging A/T/N biomarkers in predicting cognitive decline and evaluate the impact of combining biomarkers across modalities.

Feasibility and Preliminary Efficacy of Digital Cognitive Training in Parkinson's Disease with Mild Cognitive Impairment: A Pilot Study.

Objective: Cognitive impairment is common in Parkinson's disease (PD), with few pharmacological options. We evaluated the effects of a digital cognitive training program (SUPERBRAIN), previously effective in Alzheimer's risk populations, on cognitive function in PD.

Methods: Twenty-nine patients with PD and mild cognitive impairment (PD-MCI) from four clinics were randomized to intervention (n=16) or control (n=7).

Mapping Alzheimer's disease pathology using free water through integrated analysis of plasma biomarkers, microstructural DTI metrics, and macrostructural MRI measures.

Alzheimer's disease (AD) is characterized by amyloid-beta (Aβ) and tau pathologies that drive neuroinflammation and neurodegeneration. Free water (FW), a diffusion tensor imaging (DTI) metric reflecting extracellular fluid changes, has emerged as a sensitive marker of neuroinflammation. This study examined the role of FW in AD and its associations with plasma biomarkers, brain structural measures, and cognitive decline.

Integrating MRI Volume and Plasma p-Tau217 for Amyloid Risk Stratification in Early-Stage Alzheimer Disease.

Background And Objectives: Identifying β-amyloid (Aβ) positivity is crucial for selecting candidates for Aβ-targeted therapies in early-stage Alzheimer disease (AD). While Aβ PET is accurate, its high cost limits routine use. Plasma p-tau217 testing offers a less invasive option but also incurs additional costs.

Plasma phosphorylated tau 217 and amyloid‑β 42/40 for amyloid risk in subgroups.

Background: Alzheimer's disease (AD) is characterized by the accumulation of amyloid-β (Aβ) pathology. Recently, plasma biomarkers, particularly p-tau217, have emerged as promising tools for early diagnosis and risk stratification. In this retrospective study, we evaluated the diagnostic performance of p-tau217 combined with other plasma biomarkers in distinguishing Aβ Positron emission tomography (PET) positivity in cognitively unimpaired (CU) and cognitively impaired (CI) individuals across diverse clinical subgroups.

Potential utility of plasma pTau217 for assessing amyloid and tau biomarker profiles.

Purpose: Plasma phosphorylated tau 217 (pTau217) is a promising biomarker for Alzheimer's disease, reflecting both amyloid β (Aβ) and tau positron emission tomography (PET) results. While its diagnostic role is actively being investigated, this study aims to expand its application to staging disease progression and predicting cognitive decline.

Methods: A total of 2,919 participants, primarily diagnosed as Alzheimer's clinical syndrome, were recruited.

A novel deep learning-based brain age prediction framework for routine clinical MRI scans.

Physiological brain aging is associated with cognitive impairment and neuroanatomical changes. Brain age prediction of routine clinical 2D brain MRI scans were understudied and often unsuccessful. We developed a novel brain age prediction framework for clinical 2D T1-weighted MRI scans using a deep learning-based model trained with research grade 3D MRI scans mostly from publicly available datasets (N = 8681; age = 51.

Validation of criteria for frontotemporal dementia with right anterior temporal lobe predominance.

Introduction: Frontotemporal dementia (FTD) with right anterior temporal lobe (rATL) predominance lacks universally agreed-upon diagnostic criteria. This study validated the Amsterdam diagnostic tree (ADT) for right temporal variant FTD (rtvFTD) and the diagnostic criteria for semantic behavioral variant FTD (sbvFTD), examining clinical, behavioral, and imaging differences.

Methods: The study included 138 patients with behavioral variant FTD and 87 with semantic variant primary progressive aphasia who had 3D T1-weighted magnetic resonance imaging scans.

Integrating visual assessments and quantification methods for tau PET staging.

Introduction: We compared visual assessments and quantification methods for tau positron emission tomography (PET) staging and evaluated plasma biomarkers and cognitive trajectories across amyloid and tau (AT) staging.

Methods: Tau PET scans from 289 Korea-Registries to Overcome Dementia and Accelerate Dementia Research (K-ROAD) participants were analyzed visually and quantitatively, with validation in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort (n = 870). Plasma biomarkers and cognitive measures were evaluated across AT stages.

Tailoring thresholds for interpreting plasma p-tau217 levels.

Background: Plasma phosphorylated tau (p-tau) 217 test has emerged as a minimally invasive and accessible alternative to positron emission tomography imaging and cerebrospinal fluid analysis for Alzheimer's disease (AD) diagnostics. However, the diagnostic performance of p-tau217 across diverse cognitive and demographic subgroups remains underexplored. This multicentre cross-sectional study aimed to assess the diagnostic utility of plasma p-tau217 using a double cut-off approach in a large, diverse cohort, focusing on subgroup analyses based on cognitive status, age, sex, body mass index and ε4 carrier status.

Cerebral Amyloid Angiopathy and Downstream Alzheimer Disease Plasma Biomarkers.

Importance: As amyloid-targeted therapies have become commercially available, the monitoring of cerebral amyloid angiopathy (CAA), which is an important risk factor for amyloid-related imaging abnormalities, has received increasing attention. However, comprehensive evidence on the association between Alzheimer disease (AD) plasma biomarkers and various CAA imaging markers is still lacking.

Objective: To examine the association of CAA imaging markers with downstream AD plasma biomarkers in relation to amyloid-β (Aβ) uptake on positron emission tomography (PET) and whether their interplay is associated with cognitive changes.

Eligibility for Lecanemab Treatment in the Republic of Korea: Real-World Data From Memory Clinics.

Background And Purpose: We aimed to determine the proportion of Korean patients with early Alzheimer's disease (AD) who are eligible to receive lecanemab based on the United States Appropriate Use Recommendations (US AUR), and also identify the barriers to this treatment.

Methods: We retrospectively enrolled 6,132 patients with amnestic mild cognitive impairment or mild amnestic dementia at 13 hospitals from June 2023 to May 2024. Among them, 2,058 patients underwent amyloid positron emission tomography (PET) and 1,199 (58.

Impact of sleep apnea on alzheimer's disease in relation to sex: an 8-year longitudinal follow-up study of a nationwide cohort.

Background: We aimed to investigate the association between sleep apnea and incident dementia (dementia of the Alzheimer type [DAT] and vascular dementia) and whether differences in the effects of sleep apnea on dementia depend on sex. Furthermore, we sought to determine whether obesity affects the sex-specific relationship between sleep apnea and dementia.

Methods: We used de-identified data on patients with sleep apnea and a control group aged ≥ 50 years from the Korean National Health Insurance Service.

Profile for Brain Disease Research Infrastructure for Data Gathering and Exploration (BRIDGE) Platform.

Brain diseases complexity have necessitated advanced research platforms for better understanding, treatment, and prevention strategies. However, existing brain disease registries face limitations such as incomplete variable sets, lack of standardization, insufficient linkage to external databases, absence of integrated platforms for comprehensive data collection, and lack of continuity. To address these challenges, the Korea National Institute of Health initiated the Brain disease Research Infrastructure for Data Gathering and Exploration (BRIDGE), a national prospective platform designed to overcome the shortcomings of current registries.

Temporal Dynamics and Biological Variability of Alzheimer Biomarkers.

Importance: Understanding the characteristics of discordance between plasma biomarkers and positron emission tomography (PET) results in Alzheimer disease (AD) is crucial for accurate interpretation of the findings.

Objective: To compare (1) medical comorbidities affecting plasma biomarker concentrations, (2) imaging and clinical features, and (3) cognitive changes between plasma biomarker and PET discordant and concordant cases.

Design, Setting, And Participants: This multicenter cohort study, conducted between 2016 and 2023, included individuals with unimpaired cognition, mild cognitive impairment, or Alzheimer-type dementia, who had both amyloid β (Aβ) PET imaging and plasma biomarkers.

A material dynamically enhancing both load-bearing and energy dissipation capability under cyclic loading.

Material properties gradually degrade under cyclic loading, leading to catastrophic failure. It results in large costs for inspection, maintenance, and downtime. Besides, materials require combinations of performance such as load bearing and energy dissipation.

Differential roles of Alzheimer's disease plasma biomarkers in stepwise biomarker-guided diagnostics.

Introduction: This study aimed to investigate the differential roles of various plasma biomarkers in a stepwise diagnostic strategy for Alzheimer's disease (AD).

Methods: A total of 2984 participants, including 666 cognitively unimpaired (CU), 2032 with Alzheimer's clinical syndrome (ACS), and 286 non-ACS individuals, were recruited. Plasma amyloid beta (Aβ) 42/40, four phosphorylated tau (p-tau) epitopes, glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL) levels were measured using immunoassays.

Postural instability and gait disturbance are associated with abnormal stereopsis in Parkinson's disease.

Background: Visual dysfunction, including abnormal stereopsis, is a significant non-motor symptom in Parkinson's disease (PD) that can reduce quality of life and appears early in the disease. Abnormal stereopsis is associated with worsening of bradykinesia and freezing of gait, though the exact pathways linking stereopsis to motor symptoms remain unclear. Furthermore, in PD patients, the pedunculopontine nucleus and laterodorsal tegmental complex play an active role in sensorimotor control, and these areas provide cholinergic projections.

Association between focal amyloid deposition and cognitive impairment in individuals below the amyloid threshold.

Purpose: This study aimed to investigate the characteristics of individuals with amyloid levels below the threshold. To achieve this, we differentiated between two groups: those with global amyloid negativity but focal deposition [G(-)F(+)] and those without focal deposition [G(-)F(-)].

Materials And Methods: A total of 2,677 participants were diagnosed with cognitive unimpairment (CU) or mild cognitive impairment (MCI).

Plasma Alzheimer's disease biomarker variability: Amyloid-independent and amyloid-dependent factors.

Introduction: We aimed to investigate which factors affect plasma biomarker levels via amyloid beta (Aβ)-independent or Aβ-dependent effects and improve the predictive performance of these biomarkers for Aβ positivity on positron emission tomography (PET).

Methods: A total of 2935 participants underwent blood sampling for measurements of plasma Aβ42/40 ratio, phosphorylated tau 217 (p-tau217; ALZpath), glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL) levels using single-molecule array and Aβ PET. Laboratory findings were collected using a routine blood test battery.

Association Between Body Mass Index Changes and All-Cause Mortality in Parkinson's Disease.

Background: Whether body weight changes are associated with Parkinson's disease (PD) mortality remains uncertain.

Objective: To investigate the association between changes in body mass index (BMI) and all-cause mortality in patients with PD.

Methods: This nationwide cohort study enrolled 20,703 individuals with new-onset PD (ICD-10 code: G20 and a rare intractable disease registration code: V124) who underwent health screening program by the Korean National Health Insurance Service within two years from pre- and post-PD diagnosis.

Sarcopenia is a predictor for Alzheimer's continuum and related clinical outcomes.

Low body mass index is closely related to a high risk of Alzheimer's disease (AD) and related biomarkers including amyloid-β (Aβ) deposition. However, the association between sarcopenia and Aβ-confirmed AD remains controversial. Therefore, we investigated the relationship between sarcopenia and the AD continuum.